低温时效对铍材尺寸稳定性的影响

Effects of Low-Temperature Aging on Dimensional Stability of Beryllium

利用拉曼光谱仪、纳米压痕仪、电子背散射衍射电镜以及透射电镜分析低温时效后等静压铍材的残余应力、晶粒取向差、位错密度及位错分布形态,分析低温时效处理对铍材尺寸稳定性的影响。结果表明,低温时效处理后,热等静压铍材、退火铍材和热冷循环铍材在热循环过程中的尺寸收缩均明显减小。低温时效处理过程中铍材尺寸稳定化机制主要是晶粒内位错均匀化及微塑性变形导致取向差均匀化。

To improve its dimensional stability,the microstructure and residual stress of hot isostatically-pressed beryllium were regulated by low-temperature aging.Results show that after low-temperature aging,the dimensional shrinkages of hot isostaticallypressed beryllium,annealed beryllium,and thermal-cold cycled beryllium are evidently reduced.Various stabilizing mechanisms,including dislocation homogenization and coordinated grain micro-deformation,are observed during low-temperature aging,which effectively improve the dimensional stability of hot isostatically-pressed beryllium.